1362592 - Amazon page load's Time to First Paint is slower in Firefox than Chrome

Status: RESOLVED DUPLICATE of bug 1362068

(Core :: General, defect)

Description

[Chris Peterson [:cpeterson]]

In bsmedberg's page load test using external HDMI recording, he saw that Firefox was slower than Chrome for the following Amazon URL:

https://www.amazon.com/s/url=search-alias%3Daps&field-keywords=laptop

Firefox Nightly 55
Time to First Paint: 34.25 video frames = 548 ms
Time to Hero Element: 35.5 video frames = 568 ms

Chrome Beta (58?)
Time to First Paint: 30.5 video frames = 488 ms
Time to Hero Element: 32.25 video frames = 516 ms

Something seems to be delaying Firefox's Time to First Paint because Time to Hero Element is short after first paint.

Comment 1

[Benjamin Smedberg]

Here is the correct procedure for profiling:

* Load https://www.amazon.com/
* Wait for the page to finish loading
* Type "Lord of the rings" in the search box
* Time first-nonblank paint
* Record when the first non-sponsored result is painted in the correct position with its image

Note that I expect it could be important to do this from the amazon UI and not as a bare pageload, because of unload scripts, GC and whatever else.

I don't recognize the data from comment 0. Here's the data I have for the amazon search page (all means):

Chrome firstpaint: 18.25 frames/304ms
Chrome hero: 51.75 frames/862.5ms

Firefox firstpaint: 35 frames/583ms (~90% worse)
Firefox hero: 60.75 frames/1013ms (~20% worse)

This data has fairly large variance and was done against live sites, which is why I hadn't yet filed this bug report, although even with the variance we show a significant different in firstpaint.